The inventive concept relates to a method of forming patterns of a semiconductor device, and more particularly, to a method of forming a plurality of fine pitch patterns by using a double patterning process so as to exceed the resolution limits of typical exposure equipment.
Fine patterns are essential when manufacturing highly integrated semiconductor devices. In order to integrate a large number of devices within a small region, an individual device should be formed as small as possible and, for this, a pitch of a pattern to be formed should be small. Currently, as design rules of semiconductor devices are being greatly reduced, in a photolithography process for forming patterns required to realize a semiconductor device, it is difficult to form fine pitch patterns due to a resolution limit. In particular, when performing a photolithography process for forming line and space (L/S) patterns on a substrate, it is difficult to form a plurality of fine pitch patterns due to the resolution limit.
In order to cope with the resolution limit in a photolithography process, methods of forming fine pitch hardmask patterns by using a double patterning process have been suggested. However, these processes have high manufacturing costs due to expensive equipment, and are also time consuming. Also, when an etching mask material is vapor-deposited in an aperture region having a larger aspect ratio in a double patterning process, defects such as voids may occur.